Expression and purification of nuclease-free protocatechuate 3,4-dioxygenase for prolonged single-molecule fluorescence imaging.

ABSTRACT: Single-molecule (SM) microscopy is a powerful tool capable of visualizing individual molecules and events in real time. SM imaging may rely on proteins or nucleic acids labelled with a fluorophore. Unfortunately photobleaching of fluorophores leads to irreversible loss of signal, impacting the collection of data from SM experiments. Trace amounts of dissolved oxygen (O₂) are the main cause of photobleaching. Oxygen scavenging systems (OSS) have been developed that decrease dissolved O₂. Commercial OSS enzyme preparations are frequently contaminated with nucleases that damage nucleic acid substrates. In this protocol, we purify highly active Pseudomonas putida protocatechuate 3,4-dioxygenase (PCD) without nuclease contaminations. Quantitation of Cy3 photostability reve

SUBMITTER: Senavirathne G 

PROVIDER: S-EPMC6076860 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature